Fuel injection system for compression ignition engines



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J. WEBER FUEL. INJECTION SYSTEM FOR COMPRESSION IGNITION ENGINES Filed 001.. 29, 1951 Nov. 25, 1952 Patented Nov. 25, 1952 FUEL INJECTION SYSTEM FOR COMPRES- SION IGNITION ENGINES Johannes Weber, Stuttgart-Feuerbach, Germany,

assignor to Robert Bosch G. m. b. 11.,

Germany Stuttgart,

Application October 29, 1951, Serial No. 253,720 In Germany November 6, 1950 3 Claim The invention relates to a fuel injection system for compression ignition engines of the kind embodying a speed governor having an adjustment member or sleeve which with decreasing engine speed tends to move a control rod arrangement, which determines the supply quantity adjustment of the injection pump and which includes an intermediate lever which co-operates with a stop member for limiting the full load fuel quantity, which lever is also engaged by a second optionally actuable adjustment member for altering the fuel supply quantity such that on movement of either of said adjustment members the point of engagement of the other serves as a fulcrum for the intermediate lever.

The object of this invention is to provide a device for a fuel injection system which limits the fullload fuel quantity and which for the purpose of simplifying the starting operation of the compression ignition engine enables a supply of fuel to the engine to be obtained in excess of the full load quantity on the starting operation only and. not during the continued operation of the engine. A number of devices are already known which solve this problem. In these devices, however, it is necessary for the driver to carry out a particular manipulation on the installation before the actual starting operation. Therefore, a further object of this invention is to provide a device which makes it unnecessary for the driver to carry out this manipulation as it operates automatically.

According to the invention this problem is solved by so positioning a part of the rod arrangement, which co-operates with the full load stopmember, on the intermediate lever and as remote as possible from the point of engagement of the lever with the adjustment member of the centrifugal governor that when moving the optionally actuable adjustment member to effect a large supply quantity from a position which it assumes only when the engine is at a standstill or is running not faster than starting speed, the part of the rod arrangement co-operating with the full load stop member moves past the latter, thus enabling the adjustment of a supply quantity exceeding that of the full load quantity only, in this lower engine speed range.

The invention is further described with reference to the accompanying drawing, which illustrates, more or less diagrammatically, two embodiments of the invention by way of example, and in which Fig. 1 is a side elevation, partly in section, of one embodiment of the invention, and

Fig. 2 is a similar fragmentary view of another embodiment.

Referring to the drawings, mounted on the cam shaft l of an injection pump 2, which is only partially shown, is a centrifugal governor 3. The sleeve 4 of the governor which acts as an adjustment member is connected to an intermediate lever 6 by means of a pin 5. The lever 5 is flexibly or pivotally connected by means of a lug I with the regulating or control rod 8 of the injection pump which serves for varying the quantity of fuel delivered by the pump. When the lever B is moved by the displacements of the governor sleeve 4 it turns about a pin 9 which is fixed at one end of a lever IE3. This lever is disposed on a shaft H mounted in a casing l2 which encloses the entire regulating device. The shaft l I together with the lever i 0 thereon and a hand lever I3, which is mounted on the shaft outside the casing, form an optional adjustment member for use when required for varying the fuel supply quantity. When moving the adjustment lever l3, the pin 9 is displaced in a guide slot M of the intermediate lever 8 thereby moving the latter about the pin 5 on the governor sleeve 4.

The end of the intermediate lever 6 remote from the governor sleeve has a projection [5 which co-operates with a stop member It for limiting the full load fuel quantity. This stop member [6 is pivotally mounted about a fulcrum I! in a support 13. A spring l9 tends to urge the stop member l6 about its fulcrum ll so as to cause an adjustment screw 20 carried by the stop member I6 to abut against an extension 2| of the support [8.

The support [8 is fixed in the casing 12. By placing shims or Washers 22 of varying thickness between the support l8 and the casing l2 the position of the support l3 together with the stop member It can be altered so as to adjust the maximum full load quantity delivered by the injection pump.

In the drawing, the parts of the fuel regulating device and also the centrifugal governor are shown in the positions they assume when the compression ignition engine is at a standstill. If the actuating lever 13 is moved in the direction of the arrow 24, then the projection I5 of the intermediate lever 5 describes an are, shown at 23 in full lines, about the pin 5. The projection l5 of the lever can move underneath the stop member l6. Thus, the control rod 8 can be adjusted to a position in which it provides for a supply quantity exceeding that of the full load quantity.

During the operation of the compression ignition engine the pin 5 may take up the pos tion indicated, for example, by the dotted circle 5'. On moving the actuating lever I3, the intermediate lever B pivots about 5 and the projection I5 of the intermediate lever describes the are indicated at 23 in dotted lines. As shown in the drawing, this are 23 intersects the stop member I6, so that the intermediate lever 6 can only be moved up to a position where its projection I5 abuts against the stop member I6, 1. e. only to the full load position. The parts of the installation are so dimensioned that the pin 5 assumes the position 5 or a position still closer to the injection pump as soon as the compression ignition engine reaches a speed exceeding the starting speed, that is the position 5' is reached at the latest at idling speed.

The mode of operation is as follows:

In order to start the engine, the driver moves the hand lever IS in the direction of the arrow 24 and thus adjusts a supply quantity exceeding the full load quantity which is favourable for the starting operation. If the engine has started, the pin 5 assumes the position 5 or a position lying further to the right. Since in this position of the pin, as explained above, the projection I5 moves along the are 23, the projection will lift the stop member I6 when the engine starts, the stop member turning about its fulcrum I I against the resistance of the spring The driver then returns the lever l3 to the noload position or to an operational position lying below the full load position. Subsequently, the intermediate lever 6 pivots about the pin 5, which is now at least in its position 5', and the projection I5 by lifting the stop member I6 slides under the latter. The spring I9 now returns the stop member I6 downwardly to its operative position in which it limits the full load quantity. The adjusting screw 29 serves the purpose of adjusting the stop member I 6 to such an extent that the projection I5, when the engine is running at starting speed, is just able to move under the stop member I6 without touching it.

It is thus impossible, after starting the engine and during its operation, to adjust a supply quantity which exceeds the full load quantity. This can only be carried out after the engine has been stopped.

, fuel supply quantity of the pump, a control rod arrangement which includes an intermediate lever, a speed governor having an adjustment member, such as a sleeve, connected to said intermediate lever and adapted, with decreasing engine speed to move said control rod arrangement towards and against said stop member for limiting the full load fuel quantity, a second adjustment member optionally actuable for varying the fuel supply quantity and also connected to said intermediate lever such that a movement of either of said adjustment members the point of engagement of the other with the intermediate lever serves as a fulcrum for the intermediate lever, the provision of an abutment at the end of the intermediate lever remote from its connection with the speed governor member for 00- operation with said full load stop member and arranged so that it can be moved beyond said stop member by actuation of said second adjustment member only when the intermediate lever is in a position corresponding to zero or starting speed of the engine, whereby to effect adjustment of a fuel supply quantity exceeding that of the full load supply quantity.

2. In a fuel injection system according to claim 1, a pivotally mounted full load stop member and resilient means for urging it in the normal full load limiting position for co-operation with the abutment on the intermediate lever.

3. In a fuel injection system according to claim 1, an abutment pivotally mounted on the end of the intermediate lever for co-operation with the full load stop member and resilient means tending to maintain said abutment in the position in which it co-operates with said full load stop member.

JOHANNES- WEBER.

No references cited. 

